The pear pest, Cacopsylla jukyungi (Hemiptera: Psyllidae), is one of the most damaging insect to commercial pears in South Korea. In this study, we developed eight microsatellite markers specific to C. jukyungi and genotyped 132 individuals collected from 11 localities throughout South Korea. Populations showed lower observed heterozygosity than expected heterozygosity and slightly or highly positive values of inbreeding coefficients, suggesting that C. jukyungi is subjected to inbreeding. The nationwide expansion of pear orchards and the replacement with a popular new cultivar during the last 50 years, which may have accompanied the spread of C. jukyungi-bearing pear grafts and scions, are likely sources of such facilitated dispersal. Thus, a management strategy against unintended anthropogenic dispersal of the pear psyllid will be required for better control of C. jukyungi.

Pear psyllids belong to the most serious pests of pear. They damage pear trees by excessive removal of phloem sap, by soiling the fruits with honeydew which, in turn, provides a substrate for sooty mold, and by transmission of Candidatus Phytoplasma, the causal agents of the pear decline disease. The morphological similarity, the presence of seasonal dimorphism that affect adult colour, size and wing characters, and uncritical use of species names, led much confusion in the taxonomy of pear psyllid species. As a result, pear psyllids have been frequently misidentified. Here we analysed DNA barcodes of eleven pear psyllid species from eastern Asia, Europe and Iran using four mitochondrial gene fragments. The efficiency of identification was notably high and considerable barcoding gaps were observed in all markers. Our results confirm the synonymies of the seasonal forms. Previous misidentifications are also corrected. There is no evidence for the presence of European pear psyllid species in East Asia.

Nomenclatural changes are provided for Sorbus-feeding Cacopsylla moiwasana (Kuwayama, 1908) species group. Thirteen Palaearctic Cacopsylla species have been recorded from Sorbus L. (Rosaceae), and of these, seven species restricted to East Asia. Among the East Asian species, four Japanese species, i.e. C. elegans Inoue, 2004, C. jezoensis (Miyatake, 1963), C. midoriae (Miyatake, 1963) and C. moiwasana (Kuwayama, 1908), assigned to C. moiwasana species group. Above the latter three species very similar to each other, allopatrically distributed, and all or some of them could be synonymous. The present investigation of the type material resulted in confirmation that Psylla jezoensis and P. midoriae should be treated as junior synonym of P. moiwasana. The following synonyms are proposed: Cacopsylla moiwasana (Kuwayama, 1908) = Psylla jezoensis Miyatake, 1963, syn. nov., Psylla midoriae Miyatake, 1963, syn. nov. The species are newly recorded from Korea.

The confused taxonomy of the east Palaearctic pear psyllids, serious pests on cultivated pear, is reviewed. Fifty-sixnominal species have been reported from Pyrus, 25 of which we consider valid and ten as not being associated withPyrus. Our taxonomic revision suggests that, in Korea, four Cacopsylla species develop on pear. Three species occuralso in Japan. New synonyms are suggested and seasonal dimorphism are critically discussed.Key words : Psyllidae, Cacopsylla, taxonomy, host plant, Pyrus, Rosaceae, Manchrian pear, Asian pear, European pear, China,Japan, South Korea, Russian Far East

Pear psyllids are of major economic concern in Korea. In the literature five nominal species, including two West Palaearctic taxa, are reported from the Peninsula. The Korean pear psyllids, member of the large genus Cacopsylla, are reviewed here to comprise four species. Previous Korean records of C. pyrisuga (Foerster) are misidentification of C. burckhardti Luo et al. whereas those of C. pyricola (Foerster) concern C. maculatili Li and probably C. jukyungi (Kwon) stat. rev., comb. nov. (from Psylla). The latter, that is commonly found in pear orchards, occurs also in Japan where it was misidentified as C. chinensis. The differences between C. jukyungi and C. cinereosignata syn. nov. reflect seasonal dimorphism. For this reason, we synonymise the two. C. maculatili and C. qiuzili Li are shown to represent the winter and the summer form of the same species and are, therefore, synonymised as C. maculatili = C. qiuzili syn. nov. C. jukyungi and C. sandolbaea (Park & Lee) are redescribed, a key to the adult of the four species and short biological notes are provided.

Four new species of the genus Cacopsylla Ossiannilsson are described and illustrated based on adults and fifth instar immatures. Cacopsylla spp. nov. are associated with Malus baccata (L.) Borkh. (Rosaceae), Crataegus pinnatifida Bunge (Rosaceae), Aralia elata (Miq.) Seem. (Araliaceae), Pittosporum tobira (Thunb.) W. T. Aiton (Pittosporaceae) respectively. Short biological notes are provided.

Three Cyamophila species are recognized from Korea, including a new species: Cyamophila hexastigma (Horváth, 1899), Cyamophila willieti (Wu, 1932), Cyamophila sp. nov. The new species differs from other allied species in the paramere bearing a characteristic innerly protruding apex. Cyamophila dalbergiae Li, 2011, in particular, it differs also in the wing venation with the vertically narrow rectangular cell cu1 and long and sinuous vein Rs whereas in Cyamophila dalbergiae cell cu1 is broad and vein Rs relatively short and straight. In Cyamophila sp. nov. the female circumanal ring is longer than in Cyamophila dalbergiae. All three species are described and illustrated, with a key to the Korean species.

Psyllids are a serious pests of pears cultivated in temperate and subtropical regions. Pear psyllids are a member of the large genus Cacopsylla (Psyllidae: Psyllinae). Among the 28 psyllid species that infect pear trees, Cacopsylla chinensis (Yang and Li, 1981) is considered the most harmful. Recently, we found new pear psyllid pest affected Korean pear (Pyrus pyrifolia var. culta) orchards. The psyllid is morphologically identical to C. chinensis and is herein reported as a new record. In this study, we conducted DNA sequence analysis of the mitochondrial cytochrome oxidase I-leucine tRNA-cytochrome oxidase II (COI-tRNALeu-COII) and 16S rDNA regions to demonstrate the phylogenetic relationships among C. chinensis from pear orchards in Korea, and those recorded from China, Taiwan and Japan. The sequence of the COI-tRNALeu-COII and 16s rDNA regions were equivalent from Korea. Comparison of nucleotide sequences and phylogenetic analysis differentiated Korean psyllids from the Chinese and Taiwanese C. chinensis, but Korean and Japanese psyllids were closely related. The results suggest that Korean and Japanese C. chinensis are genetically homologous. It is presumable that these individuals descended from a single colony that was probably introduced recently.

회화나무이는 가로수인 회화나무에 최근 들어 발생하는 주요 해충의 하나로서 본 연구소에서는 차후의 방제시험을 목적으로 기초생태 연구를 수행하였다. 회화나무이는 1년에 월동성충과 신성충 1세대가 발생하는 것으로 추정된다. 월 동성충은 갈색형으로 4월 초순부터 5월 하순까지 발생하였으며, 우화최성기는 5 월 초순이었다. 신성충은 연두색형으로, 5월 중순부터 10월 하순까지 발생하였으 며, 5월 하순이 우화최성기였다. 난은 길이 0.31±0.02mm, 폭 0.14±0.01mm로, 촛 불 모양으로 둥글고 끝에는 갈고리형 돌기가 있다. 약충은 5령기를 거치는 것으로 조사되었으며, 1령충은 두폭 0.19±0.01mm, 체장 0.37±0.05mm, 2령충은 두폭 0.26±0.01mm, 체장 0.53±0.01mm, 3령충은 두폭 0.37±0.01mm, 체장 0.76±0.03mm, 4령충은 두폭 0.42±0.02mm, 체장 0.78±0.03mm, 5령충은 두폭 0.58±0.02mm, 체 장1.90±0.03mm이다. 향후 회화나무이의 정확한 연 발생 세대수와 월동처 구명 등이 진행될 계획이다.

The pear psylla, Cacopsylla pyricola Foerster (Homoptera: Psyllidae), is a serious insect pest of commercial pear crops. The species, which resides on pear trees throughout its life cycle, is rapidly spreading in some regions of the world. Given the life cycle, it is unclear how such a rapid spread has been facilitated. Presently, the population genetic structure of the species including genetic diversity and gene flow was studied to understand the nature of dispersal and field ecology of the species. Pear psylla was collected from several pear orchards in Korea. The 658-bp region of mitochondrial COI gene and the 716-bp long complete internal transcribed spacer 2 (ITS2) of the nuclear ribosomal DNA were sequenced. Unlikely other previously studied insect pests, the COI-based genetic diversity of the pear psylla was extremely low (maximum sequence divergence of 0.15%). This finding allowed us to conclude that the species may have been introduced in Korea relatively recently, possibly with the phenomenon of genetic bottlenecks. ITS2 sequence-based analyses of phylogeny, population differentiation, gene flow, and hierarchical population structure all concordantly suggested that the pear psylla populations in Korea are neither genetically isolated nor hampered for gene flow. These genetic data are concordant with the dispersal of an overwintering winterform morph outside the non-pear habitat in the fall and the possibility of subsequently longer distant dispersal.

지금까지 우리 나라에서 배를 가해하는 나무이과(Psyllidae) 해충은 배나무이(Cacoosylla pyrisuga)와 꼬마배나무이(C. pyricola) 두 종으로 알려져 있었으나, 정확한 생태가 아직 밝혀지지 않았다. 본 연구는 꼬마배나무이의 생태를 구명하여 방제기초 자료를 마련하고자 월동생태 및 발생소장, 온도발육 실험 등을 수행하였다. 꼬마배나무이는 겨울형 성충태로 배나무 거친 껍질 밑에서 월동하였으며, 월동성충은 2월 중순경부터 활동을 시작하였다. 성충과 약충이 배나무 잎이나 과실을 흡즙하면서 그을음병을 유발시켜 피해가 발생하였다. 꼬마배나무이의 포장발생 정도는 이상저온이었던 1993년에는 연중 다발생되었고, 한발고온이었던 1994년에는 7월 이후 발생이 급격히 감소하였으며, 기온이 평년수준이었던 1995년에는 7~8월에 발생이 감소하는 경향이었으나 9, 10월 발생이 다시 증가하는 특성을 보였다. 꼬마배나무이 알의 온도별 발육기간은 15, 20, 25, 30, 에거 각각 13.33, 9.32, 7.82, 6.60, 7.75일 이었으며, 1영에서 5영까지 온도별 발육기간은 15, 20, 25, 에서 각각 33.75, 23.77, 15.21, 17.40일 이었다. 고온영역에서 꼬마배나무이의 발육기간은 증가하였고 사망률도 증가하였다. 또한 온도와 꼬마배나무이 발육율과의 관계를 비서형 발육모형과 선형발육모형을 통하여 검토하였다.

광 및 온도가 꼬마배나무이의 겨울형성충(월동형) 발생에 미치는 영향을 조사한 결과 수원지역(북위 16') 의 꼬마배나무이 개체군은 광길이가 14시간일 때 부터 겨울형성충이 출현하였으며 광길이가 13시간일 때 9 93% 이상의 겨울형성충이 발생하였다. 또한 , 의 두 온도조건에서 겨울형성충 발생에 차이가 없었다. 꼬마배나무이의 각 발육단계별로 단일조건에 처리한 결과 1,2령기에 처리된 것은 각각 67.2, 54.4%가 겨 울형으로 되었고, 3령기는 9.3% 였으며 4령기부터는 영향을 받지 않았다. 꼬마배나무이의 평균산란수는 겨울형성충이 486.4개, 여름형성충이 387.2개 이었으며, 산란기간은 각각 34일과 24일 이었다.